A highly efficient I2-promoted formal [4 + 2] cycloaddition
enables the synthesis of 2-acylquinolines from methyl ketones and arylamines
using 1,4-dithane-2,5-diol as an ethylene surrogate. This reaction occurred via
an iodination/Kornblum oxidation/Povarov/aromatization sequence with an important role of the arylamine substrate in promoting the reaction.